Decision Tree from scratch

Alexey Novakov published on

5 min, 817 words

Cropped view of one the region in the middle of the tree we will build further

Decision Tree classifier is one the simplest algorithm to implement from scratch. One of the benefit of this algorithm is it can be trained without spending too much efforst on data preparation and it is fast comparing to more complex algorithms like Neural Networks. In this blog post we are going to implement CART algorithm, which stands for Classification and Regression trees. There are many other algorithms in decision trees space, but we will not describe them in this blog post.

Data science practitioners often use decision tree algorithms to compare their performance with more advanced algorithms. Although decision tree is fast to train, its accuracy metric usually lower than accuracy on the other algorithms like deep feed forward networks or something more advanced using the same dataset. However, you do not always need high accuracy value, so using CART and other decision tree ensemble algorithms may be enough for solving particular problem.

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Kubernetes Operator in Scala for Kerberos Keytab Management

Alexey Novakov published on

8 min, 1452 words


Kubernetes has built-in controllers to handle its native resource such as

  • Pod
  • Service
  • Deployment
  • etc.

What if you want a completely new resource type, which would describe some new abstraction in clear and concise way? Such new resource would describe everything in one single type which would require 5-10 separate native Kubernetes resources.

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Convolutional Neural Network in Scala

Alexey Novakov published on

7 min, 1255 words

Last time we used ANN to train a Deep Learning model for image recognition using MNIST dataset. This time we are going to look at more advanced network called Convolutional Neural Network or CNN in short.

CNN is designed to tackle image recognition problem. However, it can be used not only for image recognition. As we have seen last time, ANN using just hidden layers can learn quite well on MNIST. However, for real life use cases we need higher accuracy. The main idea of CNN is to learn how to recognise object in their different shapes and positions using specific features of the image data. The goal of CNN is better model regularisation by using convolution and pooling operations.

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MNIST image recognition using Deep Feed Forward Network

Alexey Novakov published on

8 min, 1593 words

Deep Feed Forward Neural Network is one of the type of Artificial Neural Networks, which is also able to classify computer images. In order to feed pixel data into the neural net in RBG/Greyscale/other format one can map every pixel to network inputs. That means every pixel becomes a feature. It may sound scary and highly inefficient to feed, let's say, 28 hieght on 28 width image size, which is 784 features to learn from. However, neural networks can learn from the pixel data successfully and classify unseen data. We are going to prove this.

Please note, there are additional type of networks which are more efficient in image classification such as Convolutional Neural Network, but we are going to talk about that next time.

Dataset

Wikipedia MnistExamples

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